Separating diamagnetic metal from sands, &amp;c.



' No. 731,043. PATBNTBD JUNE 16, 1903.

E. GATES.

SEPARATING DIAMAGNETIG METAL FROM SANDS, 8w.

APPLIOATION FILED APR. 14. 1900. umwnn JAN. 13, 1903.

N0 MODEL;

UNITED STATES Patented June 16, 1903. PATENT OFFICE.

ELMER GATES, 0F CHEVY CHASE, MARYLAND, ASSIGNOR TO THEODORE J.

MAYER, OF WASHINGTON, DISTRICT or COLUMBIA.

SEPARATING D|AMAGNET|.C.METAL FROM SANDS, 84.0.

SPECIFICATION forming part of Letters Patent No. 731,043, dated June 16,1903. Application filed April 14, 1900. Renewed January 13. 1903. SerialNo. 138,825. (No model.)

' To all whom it may concern:

Be it known that I, ELMER GATES, a citizen of the United States,residing at Chevy Chase, Montgomery county, State of Maryland, haveinvented certain new and useful Improvements in Separating DiamagneticMetal from Sands and the Like; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it ap= pertains to make anduse the same.

My invention relates to certain new and useful improvements in theseparation of free particles of diamagnetic mcta1-such as gold, copper,or the likefrom other diamagnetic material with which it isassociated-as, for instance, in sea-sands, placer-sands, and alluvialdeposits generally.

A characteristic feature of my-inventi on consists in effecting aninitial separation and concentration of the diamagnetic metallicparticles by admixing with the sand or like material containing them aquantitysay from five to ten per cent.of magnetic sand (magnetic oxid ofiron) or a quantity of finely-divided iron, nickel, or similar magneticmaterial of relatively high specific gravity, stirrin g the mixture inthe presence of water, and per mitting it finally to settle. I haveascertained that by this expedient the particles of gold or otherdiamagnetic metal, together with the particles of magnetic material,sinkto the bottom of the containing vessel and form a lower layer or layerswherein the diamagnetic metallic particles are so entangled with the magnetic particles as to be readily separated therewith from the mainresidue of diamagnetic sand by means of ordinary magnetic separators,thereby giving as the result of this initial operation a mixture ofmagnetic material and diamagnetic metallic particles which may be atonceseparated by being Subjected to the actionof another-separatorparticularly adapted for that-purpose. During this concentratingoperation or subsequent thereto I may conveniently remove the greaterportion of the upper layers of diamagnetic sand, thereby disembarrassingthe operation from the further presence of the superfluous sand, whichwill be found to contain but little or none of the metallic particles tobe recovered.

The remainder of the mass, containing what is left of the diamagneticsand and also containing the magnetic particles and the particles ofdiamagnetic metal enmeshed therewith, is thereupon dried and subjectedto the action of apparatus of a type illustratedin the accompanyingdrawings for the purpose, first, of separating the diamagnetic sand,and, secondly,of disentangling and separating the diamagnetic metal fromthe magnetic particles. In the drawings, Figure 1 represents a sideelevation, partly in section, of apparatus adapted for the practice ofmy invention. Fig. 2 represents a plan View of a part of said apparatuswith a portion of the feed-apron shown as broken away; and Fig. 3represents an end elevation of the apparatus, partly in section.

' Similar letters of reference indicate similar parts throughout theseveral views.

Referring to the drawings, A indicates a suitable feed-hopper for thereception of the driedconcentrates hereinbefore referred to, and B afeed-apron whose upper strand passes over a brass platform or table 0,having suitable openings a, below which are located the flutedmagnet-cores b, the relation of the magnets to the apron being such thatas the magnets revolve they will Slightly j ostle the upper strand ofthe apron, and consequently the material thereon. To this end themagnet-cores b are mounted upon revoluble shafts c, carrying theenergizing-coils d, within which the shafts 0 turn freely and at a ratewhich may be graduated to be either of the same speed as that of thefeed-apron or preferably at either a greater or less speed than saidfeedapron. The feed-apron passes over the roller D and over the magneticroller E, which may conveniently consist of a hollow iron cylindermounted upon a shaft 6, which shaft carries the energizing-coils f.Below the cylinder E are located the hoppers F G.

The dried material to be mad, resulting from the preliminaryconfintration here;

Inbefore referred to and containing the d1amagnetic material and theentangled gold copper, or the like, is fed from the hopper A upon thefeed-apron B and travels upon said feed-apron in the direction indicatedby the arrow. In its passage over the feed-apron the jostling exerted bythe fluted magnets 1) upon the feed-apron causes the particles ofgreater specific gravity to settle toward the surface of the apron. Theaction of the magnets 1), moreover, causes the apron to be pulleddownward slightly into the successive spaces existing between thecorrugations of said magnets. This downward pull upon the belt is due tothe attraction exercised by the magnets 17 upon the magnetic material onthe upper surface of the belt and results in further entangling the goldor other diamagnetic metal with the magnetic particles and causes theentangled material to arrange itself in a series of ridges transverse tothe longitudinal movement of the feed-apron.

The magnetic material, with the entangled gold or other diamagneticmetal, is thus finally brought to the bottom of the traveling body ofmaterial, the upper layer consisting, in the main, of diamagnetic sand.The material finally passes over the magnetic cylinder E. Thediamagnetic sand thereupon drops into the hopper F, from which it isconveyed to any suitable place of deposit. The magnetic material, on thecontrary, together with its entangled particles of gold or other diamanetic metal, is carried around by the feedapron and drops into thehopper G. From the hopper G it passes to the-second separator, whichlatter separator is of a type having the general characteristics setforth in my pending application for Letters Patent, Serial No. 9,269,filed March 19, 1900, and which I will now briefly describe.

The second separator consists of a feedapron I-I, passing over suitablerollers, as shown, and having immediately in the rear of its forwardstrand a magnet-pole K, whose core J is energized by the magnet coil L.The pole-face K of the magnet is provided with a series of zigzaggrooves, which may conveniently be filled with lead, as indicated at minFig. 3, so as to establish across the face of the magnet-pole a seriesof zigzag or wavy fields of force along which the magnetic material mustpass as it is carried along by the feedapron II.

The magnetic material containing the entangled gold or the like isdropped from the hopper G, as indicated, and immediately collects uponthe face of the feed-apron H and establishes itself thereon in wavylines corresponding to the Wavy or zigzag fields of force of themagnet-pole K. As fully set forth in my application referred to, themagnet-coil L must be energized to just such a degree as to formfrondlike structures which continually change their distribution andarrangement in their endeavor to follow the wavy or zigzag lines offorce as the feedapron I-I carries the structures over the face of themagnet-pole. The particles of gold or other diamagnetic metal becomedisentangled and sifted out from the diamagnetic material during thisoperation and fall into a receiving-hopper M. The magnetic material,

being held to the feed-apron by the attraction of the pole, is carriedon inthe direction indicated by the arrow and may be either swept fromthe apron or may accumulate at the extreme end of the magnet-pole anddrop off by gradual accretion, or the attraction at or near the end ofthe magnet-pole may be neutralized by locating in the rear of theextreme end of the magnet-pole a large body of soft iron, as indicatedin dotted lines, for the purpose of diverting the magnetic lines offorce into the said body of soft iron, as will be readily understood.

When in the preliminary construction referred to I employ particles ofmetallic iron, I make them of approximatelynniform size and preferablyload them-i. e., increase their specific grav'ityfby coating theindividual particles with lead or the like or otherwise mechanicallyassociating them individually therewith.

It will of course be understood that the magnets 72 may be energized inother ways than by the coils d. Moreover, the magnet E may be stationaryinstead of revoluble and may be energized in any othersuitable mannerthan that shown. So, also, the separator for disentangling andseparating the diamagnetic metal from the magnetic material may bevaried in its detailed structure, provided it retains the basalprinciples of operation upon which its action depends. In fact, while Iregard the illustrated structure as peculiarly adapted to the practiceof my invention, my invention, broadly considered, is not limited to itsspecific details. For instance, so far as I am aware, it is broadly newto concentrate particles of diamagnetic metal from a mixture ofdiamagnetic material containing them by causing said particles to beentangled or enmeshed with magnetic material added to the mass and tosubsequently disentangle the gold from the concentrate. I desire,therefore, that my claims hereunto annexed be given an interpretationcommensurate with their fair imort. p Having thus described myinvention, what I claim is 1. In the art of separating free particles ofdiamagnetic metal (such as gold, copper, and the like), from otherdiamagnetic material (such as sand) with which they are associated, thepreliminary method'of first roughly segregating the diamagnetic metalfrom the mass, and then separating the remaining sand from thesegregated material, which consists in admixing particles of magneticmaterial with the mass, enmeshing or entangling the diamagnetic metallicparticles thereby, concentrating the combined metallic particles anddiamagnetic metallic particles, and removing the remaining sandtherefrom, by passing the concentrate through a magnetic field, anddivertin g the mixture of magnetic particles and diamagnetic metallicparticles into a different path of collection from that of the particlesof sand; substantially as described.

terial and diamagnetic metal, by passing the a concentrate through adirecting magnetic field of force; and then passing the said mixturethrough a magnetic field of such graduated force as to cause theparticles to arrange themselves in frond-like structure, causing asuccession of rearrangements of said structures, thereby disentanglingthe diamagnetic metallic particles therefrom, and collecting saiddiamagnetic metallic particles as they become disentangled substantiallyas described.

In testimony whereof I affix my signature in presence of two witnesses.

ELMER GATES.

WVitnesses:

JOHN C. PENNIE, J. E. HUTCHINSON, Jr.

